Lymph node ratio as an independent predictor of survival in pancreatic adenocarcinoma: Insights from a retrospective cohort study

Objectives We evaluated the prognostic impact of lymph node yield (LNY) and lymph node ratio (LNR) on disease-free survival (DFS) and overall survival (OS) after resection for pancreatic adenocarcinoma. Methods Using a retrospective cohort of 214 patients who had undergone surgical resection between 2000 and 2022), LNY was dichotomized at the median (≤13 vs >13 nodes). The LNR was categorized as 0, 0.01 to 0.20, and greater than 0.20. Survival was analyzed using Kaplan-Meier/log rank and multivariable Cox regression; node-negative category (N0) sensitivity analyses were performed. Results The LNY was not significantly associated with differences in DFS (14 vs 15 months; P = .72) or OS (18 vs 26 months; P = .27), although N0 patients showed a trend toward longer OS with higher LNY (22 vs 36 months; P = .087). The LNR statistically significantly separated DFS (19 vs 10 vs 12 months; P = .003) and OS (28 vs 20 vs 18 months; P = .045). In Cox models, an LNY below 13 was protective for DFS (hazard ratio [HR], 0.633; P = .03) and borderline for OS (HR, 0.705; P = .07). Compared with an LNR of 0, an LNR of 0.01 to 0.20 or greater than 0.20 independently predicted recurrence (HR, 1.921; P = .006 and HR, 1.745; P = .02); for OS, only an LNR greater than 0.20 remained significant (HR, 1.752; P = .01). A higher LNR was associated with lymphovascular/perineural invasion and progression. Conclusions Lymph node ratio is an independent prognostic marker after resection that predicts recurrence and—when above 0.20—mortality, whereas LNY mainly reflects staging adequacy.